The reaction of methanol and oxygen is known in the prior art. This reaction has been catalyzed by various catalytic species such as platinum, gold and palladium.
In U.S. Pat. No. 4,304,761 various oxidation routes for methanol are set forth including the reaction of methanol with oxygen to produce carbon dioxide and water. In that patent, experiments were conducted to arrive at a system for reducing methanol emissions from internal combustion exhaust gases. Large excesses of oxygen were utilized, wherein the oxygen to methanol ratio was 6.25, which is more than four times the stoichiometric requirement. Complete conversion of methanol requires temperatures of at least 125.degree. C. (257.degree. F.). At temperatures lower than the recited temperature, the methanol oxidized incompletely thus forming formaldehyde byproduct. The patent teaches that in order to get complete oxidation of methanol to carbon dioxide and water one should use stoichiometric excesses of oxygen and temperatures above 125.degree. C., well above ambient conditions. The catalysts demonstrated for activity included platinum, palladium, rhodium and silver.
In an article by Collin N. Hodges and Leonard C. Roselar entitled Gold and Platinum Catalyzed Oxidation of Methanol appearing in the Journal of Applied Chemical Bio-Technology 1975 vol. 25 pages 609 to 614, the oxidation of methanol under oxygen deficient conditions (oxygen/methanol=0.5 mol fraction) using a platinum gauze catalyst was studied. The article indicates that the lowest reaction temperature of 150.degree. C. (302.degree. F.) resulted in the formation of formaldehyde. It required temperatures of 190.degree. to 225.degree. C. (374.degree. to 437.degree. F.) to produce a hydrogen or carbon dioxide product from methanol oxidation over a platinum catalyst. There is no suggestion in that article that lower temperatures, particularly temperatures approximating ambient, could result in complete conversion of methanol or any suggestion as to what reaction of near stoichiometric amounts of methanol and oxygen would accomplish.
In another article by J. G. Firth entitled Catalytic Oxidation of Methanol Over Platinum appearing in TransFaraday Society 1971 Volume 67 page 212, the oxidation of methanol was studied under conditions of excess oxygen (oxygen to methanol ratios of 2.5 up to 20) using a platinum catalyst. Some platinum catalyst activity was observed at ambient temperatures of 27.degree. C. (80.6.degree. F.), but at those temperatures methanol conversion was relatively low.
None of the above prior art suggests the viability of feeding a commercial inert gas stream that is contaminated with oxygen along with a stoichiometric quantity of methanol at ambient temperature to a reactor with no external heating, that effectively results in complete conversion of methanol and oxygen to innocuous byproducts of carbon dioxide and water. The present invention achieves such a result using appropriate catalyst to result in an efficient economical oxygen scavenging process as set forth below.